Lock-stitch sewing machine



11,462.58? 1 L. E. TOPHAM LOCK STITCH SEWING MACHINE Filed July 11, 1919 2 Sheets-Sheet 1 July 24, 1923.

L. E. TOPHAM LOCK STITCH SEWING MACHINE Filed July 11, 1919 2 Sheets-Sheet 2 Patented July 24;, 1923.

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LAURENCE n. TOPI-IA-M, orswnnrsoorcr, MASSACHUSETTS,

ASSIGNOR 'I'O UNITED OF NEW JERSEY.

Application filedifuly 11, 1919.

T0. allwizom it may concern:

Be it known that I, LAURENCE E. Tor- HAM, a citizen of the United States, resid- ,ing at Swampscott, inthe county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Lock-Stitch Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to outsole lock-stitch sewing machines.

The invention is intended primarily as an improvement in the machine of Patent 473,870, April 26,1892, although not confined in its application thereto, and its object is to so improve the mode of operation of the stitch forming and work feeding instrumentalities that the speed of operation may be increased.

In the machine of the above patent, the work is fed by the awl which is so actuated that it enters the work after the stitch has been set by the take-up so that during that part of the cycle in which the awl is in the work there is no manipulation of the thread on the needle side, and consequently the thread handling devices are practically idle during this period. This mode of operation therefore limits the interval during which the shuttle and take-up must act, and con sequently the speed of the machine.

In accordance with the present invention, the awl is so actuated that it enters the work after the needle has withdrawn with its thread and withdraws before the take-up sets the stitch. The needle, thread lifter or looper, and the shuttle may therefore act on the thread while the awl is in the work, and the interval in each cycle during which the shuttle and take-up act may be lengthened, thereby permitting the speed of operation to be increased. At the same time, the awl is free of the work during the operation of the take-up so that it as well as the needle will not crowd the work against the thread in the needle hole and interfere with the proper and uniform setting of the stitch.

The invention is illustrated in the acc0mpanying drawings, in which Fig. 1 is a side elevation of a machine embodying the invention; Figs. 2-6 are diagrammatic views LOCK-STITCH SEV/ING MACHINE.

Serial No. 310,245.

mechanism.

The machine shown in the drawings is provided with an awl- 2, a hook needle .L (Fig. 7), a looper 6, a shuttle 8, a thread lifter 10, a take-up 12, a work table 1%, a presser-foot l6 and afeed slide 18 on which the awl is mounted, all of which are the same in construction as the corresponding parts in the machine of the patent referred to, and all of which, with the exception of the needle, are actuated through mechanisms which are fully shown and described in said patent. The operating cams. on the cam shaft 20 are shaped to actuate and time the parts in the manner hereinafter described.

In embodying the invention in the machine of the patent, the needle actuating mechanism (indicated in Fig. 7 is preferably utilized. The toothed part 22 of the needle segment is shortened, as compared with the needle segment of the patent, so that it will not interfere with the shuttle. Motion is transmitted from the cam operated segment 26 to the needle segment through two intermediate pinions 24 which operate simultaneously and successively to connect the two gear segments during their oscillation and to enable the requisite stroke to be given to the needle through the comparatively short segment 22.

The cycle of operations is indicated in Figs. 2-6. After the thread has been laid in the hook of the needle (as indicated in Fig. 2), the needle is withdrawn, carrying the loop through the work (as indicated in Figs. 3 and a). After the needle has emerged from the upper side of the work, the awl advances and enters the work (as indicated in Fig. l), the needle completing its backward stroke, and the thread lifting finger taking the needle loop and presenting it to the shuttle which starts through the needle loop (as also indicated in Fig. 4c). lVhile the shuttle is passing through the loop, the awl moves in the direction of the feed into register with the needle and advances the work a stitch length. The awl is withdrawn as the shuttle casts off the loop and as the take-up is about to act to set the stitch (as indicated in F ig. 6). The thread handling devices are thus acting upon the thread during the time that the awl is in the work and is moving in the direction of feed, and the awl is free of the work when the take-up is acting to set the stitch, so that it as well as the needle will not in terfere with the free and proper reeving of the thread through the work and the proper drawing of the locking-thread to a uniform depth in the work. The increase in the length of the operating interval for the shuttle and take-up, secured by this manner of actuating the awl, permits the cams to be given shapes better suited for high speed operation and thus enables the speed of the machine to be materially increased.

While the invention has been shown and described as embodied in the machine of the patent above referred to, in which the awl effects the entire feed of the work, it will be understood that it is not limited in its application to this machine or to machines in which the awl effects the entire feed, but it may be embodied with advantage in other awl feed machines, or in machines in which an awl reciprocating in the line of feed co-operates with other stitchforming and work engaging devices in effecting the feed.

What is claimed is:

1. A look stitch sewing machine having,

in combination, a work feeding awl, a hook needle, a looper, a shuttle, a stitch setting take-up, means for actuating the awl to feed the work, means for causing the awl to enter the work after the needle withdraws with its loop of thread from the work and to withdraw from the work before the takeup takes up said loop and sets the stitch, and means for actuating the take-up to set the stitch after the awl has withdrawn and before the needle again enters the work.

2. A look stitch sewing machine, having, in combination, an awl, a hook needle, a looper, a shuttle, a stitch setting take-up, means for reciprocating the awl in the line of feed, means for causing the awl to enter the work after the needle withdraws with its loop of thread from the work and to withdraw from the work before the takeup takes up said loop and sets the stitch, and means for actuating the take-up to set the stitch after the awl has withdrawn and before the needle again enters the work.

3. A lock-stitch sewing machine having, in combination, an awl, a hook needle, a looper, a shuttle, a stitch setting take-up, a needle carrying segment, an actuating segment and two intermediate pinions each arranged to engage the two segments.

LAURENCE E. TOPHAM. 

